1. Field of the Invention
The present invention relates to a light emitting device and a method for producing the same.
2. Description of the Related Art
In recent years, light emitting devices utilizing electroluminescence (EL) elements have been developed. For example, in a light emitting device utilizing an organic EL element, a first electrode, an organic EL layer including at least a light emitting layer, and a second electrode are sequentially laminated on a supporting substrate such as glass, and the organic EL element is sealed with a sealing substrate such as glass, in order to protect the organic EL element from the oxygen or moisture in the atmosphere. When the light emitting device is connected to external lines through the lead-out lines (terminals) of the two electrodes, and an electric field is applied, the holes and electrons recombine in the light emitting layer in the region interposed between the electrodes, and thereby light is emitted. A bottom emission light emitting device in which the light generated in the light emitting layer is extracted through the supporting substrate side and a top emission light emitting device in which the light is extracted through the sealing substrate side are known.
As the substrate to be used in EL displays and the like, a resin sheet in which, for example, in an epoxy resin layer, a light diffusing material having a refractive index different from that of the epoxy resin is unevenly distributed so as to have a concentration distribution in the thickness direction has been proposed (see Japanese Patent Application Laid-Open (JP-A) No. 2004-109497).
Also, in order to enhance the efficiency of extracting light in a top emission light emitting device, a method has been proposed in which a structure having a three-dimensional shape and formed from a resin material is provided on the second electrode by the imprint technology, and the light which is totally reflected between the second electrode and the air is made to enter the structure, to thereby extract light to the outside from the lateral surface of the structure (see JP-A No. 2007-265988).